We can also agree that this comet carries water in particular. Unfortunately, this has leaned heavily on the thinking of theorists and it has been supposed that as the comet approaches the sun that the increased warmth helped create a cloud. I do not think it has much to do with warming at all. Much more likely, the dust mass progressively charges up because of increased radiation from the sun. This induces charge accepting particles to separate, and of course the comet is an accumulation of dust.
I suspect that the main charge accepting particle is carbon soot. Thus a comet is a mass of fine condrite dust, water and ammonia vapor and lots of free carbon soot.